IMO, increased resistance to bolt lift is the first indication that you're reaching the higher operating pressures of your rifle and cartridge load combination. Usually, the next indicator is an ejector mark on the case head, which I would consider your rifle/loads max+. This isn't a place I personally like to call home. At the first sign of an ejector mark, I'll usually back the load down X amount (depending on cartridge) and call that max for that load.
I've seen ejector marks long before a stiff bolt. It takes years of doing this with many barrels to truly understand what is going on. I'm going off a general consensus that most of us run our loads slightly over what they should be with no or little signs of pressure. The primal rights tutorial just touches major high spots.
I see a lot of misconceptions regarding flat primers, over pressure, what's your headspace? Coupled with some of todays brass coming out with extremely deep primer pockets, heck the primer has to slam into bolt face. Then we have cratering, heck rem 700's crater by nature, now the degree of cratering is another factor.
I've seen guys who get a few rds overpressure, go home, redo without cleaning brass off their bolt face and come back and get swipes around their primer holes and call pressure, it's not pressure, it's built up brass on the bolt face and marring brass.
Nothing against H4350, but the obsession with it makes me want to pull what little hair I have left out. It's like no one is capable of branching out, the other day on a long range facebook group I belong to, a guy was shooting H4350 in a 7 saum with 180gr bullets, we're talking 80% case fill here, with a margin of error so limited.
I just had 2 6slr's built, night and day between the two, one a uber fast Hawk Hill, the other a slower Mullerworks, thank God I knew better than to try match loads between the two. Now I don't measure casehead expansion, but do decap my test loads to feel for resistance of my tested loads, with this Win brass, I had my share of gassed primers, some were hotter, others not so, really hard to differentiate with this quality of brass.
Rant over.
